Clear cart does not remove 'require other products' products

I have a main item, which is actually one of six items that must be sold as a set.  The 'require other products' works perfectly for this.  However, if I click 'clear cart,' the main product is removed but the other five (priced at $0 - since I am selling via the main product) remain in the cart and can be ordered.  Clicking clear cart a second time actually clears it.  But somehow, I don't think my customers will click it twice :)

nopCommerce doesn't come with a "clear cart" button out of the box. Are you using a plugin to add this functionality? Please report the bug to the author of the plugin.

Great - didn't realize that.  I'll follow up with them.  Thanks!